Predictive Value of the PaO2/FIO2 Ratio for Mortality in Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-analysis.

Objective Despite the controversy regarding its clinical utility, the arterial oxygen partial pressure (PaO2) to the fraction of inspired oxygen (FIO2) ratio has been used to define the severity of acute respiratory distress syndrome (ARDS). This systematic review and meta-analysis (SRMA) details summary estimates of the predictive performance of PaO2/FIO2 ratio in predicting mortality in patients with ARDS. Methods To clarify the integrated diagnostic accuracy, we included studies in which the study population comprised patients with ARDS in any clinical setting, included adult patients (≥18 years old), and evaluated mortality. The MEDLINE and Cochrane Central Registry of Controlled Trials databases were searched for articles in English. We performed SRMA on the accuracy of the diagnostic prognostic tests using the Quality Assessment of Diagnostic Accuracy Studies-2 tool to evaluate the risk of bias. We obtained summary point estimates of sensitivity and specificity and calculated the area under the receiver operating characteristic (AUROC) curve of the summary receiver operating characteristic curve with 95% confidence intervals (CIs). Results Twenty-eight trials with 38,270 patients were included in the quality assessment. Most of the studies were conducted in intensive-care units. Overall, the risk of bias is high. For PaO2/FIO2 of 100 and 200 the pooled sensitivity, specificity, and AUROC were 44.8% (95% CI, 38.1-51.7%), 70.6% (95% CI, 65.9-74.9%), 0.60 (0.58-0.64) and 83.9% (95% CI, 78.9-87.8%), 26.1% (95% CI, 20.8-32.1%), 0.64 (0.60-0.69), respectively. Conclusion The PaO2/FIO2 ratio alone did not have impressive prediction accuracy for mortality in patients with ARDS and might not be able to be used solely as a clinical prognostic tool.